Silicon is the most important semiconductor material used in microelectronic devices. As the number of transistors keep doubling every 24 months (Moore’s law), transistors continue scaling down in size, electrical interconnect is reaching its limits to keep up with the scaling down rate in integrated circuits. These limitations are related to interconnect density and power consumption. Hence, replacing electrical interconnect with optical interconnect on the chip or between chips has the ability to overcome these limitations. However, silicon has poor light emitting efficiency, and other substitutes such as III-V materials are not suitable due to high cost, lattice mismatch, and thermal mismatch with Si. Recently researchers have been developing novel group IV alloys from silicon, germanium, and tin to overcome these problems.
In this research a less developed group IV alloy, GePb, as well as GeSn, have been studied for the development of optoelectronic devices. A physical vapor deposition method is used to evaporate the solid sources in a thermal evaporator chamber to deposit the films on a Si substrate. The GeSn and GePb samples were deposited at room temperature then annealed in a Fisher Scientific furnace at different temperatures (300-600 °C) and times (15-60 min). Material and optical characterization of the samples was performed using Raman spectroscopy, X-ray diffraction, photoluminescence, and scanning electron microscopy
